US Mass Shootings Over Time

The number of mass shootings in the US is increasing.

The year with the most shootings was 2018 which consisted of 11% of the mass shootings.

US Mass Shootings By Gender

96% of mass shooters were men.

US Mass Shootings By Race

56% of mass shooters were white.

Were There Prior Signs of Mental Health Issues?

53% of mass shooters had prior signs of mental health issues.

Were Weapons Obtained Legally?

72% of mass shooters obtained weapons legally.

US Mass Shootings By State

California is the state that has had the most mass shootings.

17% of the mass shootings were in California.

US Mass Shootings By Location Type

Putting locations classed as “Other” to one side, as we don’t know what types are included in that classification, the workplace is the most common location type for mass shootings (33%), with schools being the next most common (15%).

Age Of Shooter

Shooter ages range from 11 to 66.

Age Bracket Of Shooter

The age bracket with the highest number of mass shootings is the 20s (34% of mass shootings).

Semi-Automatic Weapons

65% of mass shootings involved semi-automatic weapons.

Multiple Weapons

53% of mass shootings involved multiple weapons.

State & Race

State & Semi-Automatic Weapons

State & Multiple Weapons

State & Weapons Obtained Legally

State & Location Type

State & Prior Signs of Mental Health Issues

State & Age Bracket

Year & Semi-Automatic Weapons

Year & Multiple Weapons

Year & Age Bracket

Year & Prior Signs of Mental Health Issues

Year & Weapons Obtained Legally

Year & Location Type

Semi-Automatic Weapons & Prior Signs of Mental Health Issues

Multiple Weapons & Prior Signs of Mental Health Issues

Multiple Weapons & Semi-Automatic Weapons

Semi-Automatic Weapons & Age Bracket

Weapons Obtained Legally & Age Bracket

Multiple Weapons & Age Bracket

Multiple Weapons & Weapons Obtained Legally

Semi-Automatic Weapons & Weapons Obtained Legally

Age Bracket & Prior Signs of Mental Health Issues

Location Type & Prior Signs of Mental Health Issues

Weapons Obtained Legally & Prior Signs of Mental Health Issues

Location Type & Age Bracket

Location Type & Semi Automatic Weapons

Location Type & Multiple Weapons

Location Type & Race

About This Data

The dashboard is powered by data on US mass shootings 1982 - 2019 and has been provided by Mother Jones.

The download is available at:

https://www.motherjones.com/politics/2012/12/mass-shootings-mother-jones-full-data/

Data Cleansing Changes - Gender

The original breakdown of number of mass shootings by gender was:

Gender Shootings
F 1
Female 2
M 36
Male 70
Male & Female 1

The cleansed breakdown is:

Gender Shootings
Female 3
Male 106
Male & Female 1

Data Cleansing Changes - Race

The original breakdown of number of mass shootings by race was:

Race Shootings
1
- 2
Asian 8
black 9
Black 9
Latino 10
Native American 3
Other 5
unclear 1
white 41
White 21

The cleansed breakdown is:

Race Shootings
Black 18
Latino 10
Native American 3
Unknown 17
White 62

Data Cleansing Changes - Weapons Obtained Legally

The original breakdown of number of mass shootings by “Weapons Obtained Legally” was:

Weapons Obtained Legally Shootings
Yes 2
- 1
Kelley passed federal criminal background checks; the US Air Force failed to provide information on his criminal history to the FBI 1
No 16
TBD 7
Unknown 6
Yes 76
Yes (“some of the weapons were purchased legally and some of them may not have been”) 1

The cleansed breakdown is:

Weapons Obtained Legally Shootings
No 16
Unknown 15
Yes 79

Data Cleansing Changes - State

A new column was added containing the state code e.g. CA for California.

In the original data, the unique states after the comma in the location column were:

State Shootings
Arizona 1
Arkansas 1
CA 5
California 14
CO 1
Colorado 5
Connecticut 3
D.C. 1
FL 2
Florida 9
Georgia 2
Hawaii 1
IL 2
Illinois 2
Iowa 1
Kansas 1
Kentucky 2
Lousiana 1
Massachusetts 1
MD 3
Michigan 2
Minnesota 2
Mississippi 1
Missouri 1
Nebraska 1
Nevada 1
New York 4
North Carolina 2
NV 1
OH 1
Ohio 2
Oklahoma 1
Oregon 2
PA 3
Pennsylvania 2
South Carolina 2
Tennessee 1
Texas 7
TN 1
TX 2
Utah 1
Virginia 1
Washington 7
Wisconsin 4

After cleansing, the unique states are:

State Shootings
AR 1
AZ 1
CA 19
CO 6
CT 3
D.C. 1
FL 11
GA 2
HI 1
IA 1
IL 4
KS 1
KY 2
LA 1
MA 1
MD 3
MI 2
MN 2
MO 1
MS 1
NC 2
NE 1
NV 2
NY 4
OH 3
OK 1
OR 2
PA 5
SC 2
TN 2
TX 9
UT 1
VA 1
WA 7
WI 4

Data Cleansing Changes - Location Type

The location types were:

Location Type Shootings
Workplace 1
Airport 1
Military 5
Other 42
Other 3
Religious 6
School 17
Workplace 35

There were 2 instances of “Workplace”" as one had a leading white space.

There were also 2 instaces of “Other”" as one with a trailing white space.

The cleansed types are:

Location Type Shootings
Airport 1
Military 5
Other 45
Religious 6
School 17
Workplace 36

Data Cleansing Changes - Prior Signs Of Mental Health Issues

The values in the imported data were:

Prior Signs Of Mental Health Issues Shootings
- 7
No 17
TBD 3
Unclear 24
Unknown 1
Yes 58

The values are now:

Prior Signs Of Mental Health Issues Shootings
No 17
Unknown 35
Yes 58